Note: It is simpler if your machine has already seen with
address assigned by DHCP. Otherwise you need to specify
the MAC address. (The virtual box's bridge adapter tab
shows the MAC address.)

Choose your Gerätename and set IP Addresse.

Check "Diese Regel aktivieren"

Note 1: You can choose the existing IP address (another
machine is using), but this causes a trouble. It is
better to avoid it. The easy way is shutdown the machine
that has a IP address you want to use when you use the
DHCP to assign the IP address.

Note 2: You cannot set the IP address outside the range
of IP-Startadresse and IP-Endadresse. The GUI allow to set
such address, but it ignored without any error (This is
not a behaviour of a high quality software).

Check the Feste IP-Adressen aktivieren and wait to update the
page.

In some case, the status does't green check. But I just repeat
it, then it worked second time for me.

Restart the Virtual machine. When restart the gurst host's
network, I obtained the new IP address, but, it becomes
"Unknown name" in the Übersicht. In order to solve
"Unknown name" in the Angeschlossenes Gerät, I needed to
restart the Guest host.

When I use "bridge adapter" on a guest OS (Kubuntu 14.04), and the
host OS (Windows 7) using Wifi, the guest OS cannot connect to the
Internet. The error message of Network Manager is "IP configuration
is unavailable".

In this case, we can use NAT. Settings of the VirtualBox, network,
then, Attach to "NAT".

The reason is most wireless adapters do not support promiscuous
mode. This means the Wifi connection only pass the packets which
has the host OS's IP address. Then, the guest OS's packets are not
visible. Thus, when the gust OS uses the NAT, then the gust OS can
connect to the outside of the host.

Then this has a clear disadvantage, the outside cannot see the guest
OS's network adapter. The motivation to use the bridge is to see
the guest OS network adapter. The guest OS uses NAT, then the guest
is invisible. But, with a Wifi connection, the guest is usually
invisible. So, when I connect to the cable, I switch the guest to
the bridge, but using Wifi, I switch the guest to the NAT. Or, if I
don't need to see the guest OS, the I can use the NAT on the guest
OS.